Influence of age on the treatment of limited-stage small-cell lung cancer.

PURPOSE: To evaluate the prognostic importance of age on response rate and survival in patients with limited-stage small-cell lung cancer (SCLC), and to determine the effect of age on chemotherapy dose delivery and toxicity. PATIENTS AND METHODS: We undertook a retrospective analysis of data from two multicenter, randomized trials conducted by the National Cancer Institute of Canada (NCIC) in which 608 SCLC patients who presented with limited disease (LD) all received the same chemotherapy. Treatment consisted of cyclophosphamide, doxorubicin, and vincristine (CAV), and etoposide plus cisplatin (EP) administered in an immediate or delayed alternating fashion, plus cranial and thoracic irradiation.
RESULTS: There were 520 patients aged less than 70 years, and 88 > or = 70. No significant differences existed between the two age groups in baseline characteristics, including treatment protocol, performance status, and serum lactate dehydrogenase (LDH) level. There were more men in the older group (P = .05). Overall response rates were comparable (78% v 82%, P = .50), and 5-year survival rates were also similar (P = .14), with 11% alive in the younger group and 8% in the older group. Age was a significant predictor of overall survival when analyzed as a continuous variable in a univariate model (P = .01), but it was no longer an independent prognostic factor in our multivariate regression analysis. An analysis of chemotherapy delivery between the two age groups showed that patients aged > or = 70 years received lower total doses of each drug compared with the intended full protocol dose, primarily as a result of dose omissions, rather than dose reductions. The frequency of dose delays was not different between groups. No significant differences were seen in the incidence of either hematologic or most nonhematologic toxicities.
CONCLUSION: Age is not a significant adverse prognostic variable in SCLC patients with LD. Moderately aggressive chemotherapy may be delivered safely to elderly patients with a good performance status, although modest attenuation of therapy through either dose reduction or omission may occur more frequently in this population.